Mr Smith, who is head of religious education at Central Foundation Girls' School in Bow, east London, also suffered a fractured skull.

The four now face a jail sentence.

Detectives made secret recordings of the gang's plot to attack Mr Smith prior to the brutal assault.

The covert audio probe captured the gang condemning Mr Smith for 'teaching other religions to our sisters', the court heard.

The RE teacher was targeted as he made his way on foot along Burdett Road in nearby Mile End on July 12 last year, Snaresbrook Crown Court was told.

Prosecutor Sarah Whitehouse told the court: 'The evidence from what was said on the probe points overwhelmingly to a religious motive for this attack.'

It is believed the gang had made two earlier attempts to get at the teacher.

They were due to stand trial for the attack at Snaresbrook Crown Court but pleaded guilty to causing grievous bodily harm with intent.

Judge John Hand QC remanded the defendants in custody until sentence on a date yet to be confirmed.

Hussein, of Bethnal Green, east London; Rashid, of Shadwell, east London; Hussain, of Wapping, east London, and Alam, of Whitechapel, east London; have all admitted causing grievous bodily harm with intent.

"To convince you of the certainty of that leadership, let me point out to you how we have turned all of the inventions of the White Man into weapons against him. His printing presses and Radios are the mouthpieces of our desires, and his heavy industry manufactures the instruments which he sends out to arm Asia and Africa against him. Europe and America are destroyed by atomic warfare, the Whites can offer no resistance against the large masses of the dark races, who will maintain an unchallenged technological superiority".